Lamp



FIG. 1 is a front elevation view of a lamp.

FIG. 2 is a side elevation view of a lamp.

FIG. 3 is another side elevation view of a lamp; and,

FIG. 4 is a back elevation view of a lamp.

The broken line showing is included for the purpose of illustration only and forms no part of the claimed design. 

The ornamental design for a lamp, as shown and described. 